This invention is directed to an aqueous composition of a water-borne resin comprising a polyester polymer and a solution polymerized acrylic copolymer which has been at least partially neutralized by a base.
Increasingly stringent policies and regulations for the protection of the enviornment have increased the need for polymeric resinous compositions having very low contents of volatile organic components, i.e., having very low VOCs ("volatile organic contents"). Polymeric resinous compositions are utilized for example in coating compositions of various types. Since the polymeric resinous material, typically employed as binder in such compositions, often makes up a substantial part of the composition as a whole, the volatile organic solvent content of the resin utilized as binder is quite important with respect to achieving a low VOC for the composition as a whole.
However, it has been difficult to achieve low VOC in water-borne systems employing solution polymerized acrylic resins, for example in systems employing a combination of acrylic and polyester resins. The removal of organic solvents from resinous compositions containing solution polymerized acrylic copolymers in attempting to achieve low VOC generally is accompanied by the significant drawback of causing the viscosity of the resin compositions to increase to an undesirable extent and may even result in gelation.
The present invention is directed to contributing to the solution of the aforesaid problems by providing an aqueous composition of a water-borne resin comprising a polyester polymer and a solution polymerized acrylic copolymer which aqueous composition has an unexpected combination of desirably low VOC and low viscosity. Other objects of the invention will become apparent to the reader infra.